Many known exercise machines are costly devices intended for use in gyms or other dedicated workout facilities. Because of their typically large size and weight, such devices are not generally portable and are not readily usable in areas such as a home living room or company office. Indeed such exercise machines are also typically dedicated to one kind of exercise motion. For example, an exercise bicycle involves circular rotation of foot pedals that are moved by the user's feet and legs. Alternatively, a treadmill involves a moving surface on which the user walks. Individuals burn calories by moving and it is not necessary to work up a sweat to burn calories.
Many known exercise devices are known that incorporate mechanical linkages. For example, a discussion of four bar linkages is found on the University of Notre Dame website, www.nd.edu, in AME 339 Kinematics and Dynamics of Machinery, Grashoffs Criterion. Also several prior art exercise devices using linkages are disclosed in the following U.S. patents: U.S. Pat. No. 4,824,10; U.S. Pat. No. 5,352,169; U.S. Pat. No. 5,836,854; U.S. Pat. No. 5,846,166; U.S. Pat. No. 5,865,712; U.S. Pat. No. 5,921,894; U.S. Pat. No. 6,454,682; and U.S. Pat. No. 6,468,184.
Many known exercise machines are relatively bulky and take up a lot of floor space. Such machines are often found at health clubs and gyms. Unfortunately, individuals are oftentimes too busy to go to a gym or a health club to exercise. As such, exercise devices have been developed that allow a user to exercise while working at a desk or sitting at home viewing TV. For example, U.S. Pat. No. 6,709,368 discloses a foot pedal exercise device that is amenable to being used while watching TV and can also be used at the office under the desk. Unfortunately, the exercise device disclosed in the '368 patent is a single function device. Users are known to become bored doing the same exercise all of the time. Moreover, multiple exercise devices are cumbersome and costly. Thus, there is a need for a multiple function exercise device that is amenable to be used in non-exercise environments, such as, at the office under a desk as well as at home while watching TV.
Therefore, it would be desirable to provide a relatively low cost, lightweight, portable, easy to use, quiet, and reliable exercise device for use in non-exercise environments, such as an office or home living room. The device should be configured so that the user can easily alternate the types of movement involved in order to exercise different muscle groups and to vary the exercise session so that it does not become overly tiring or boring. Optionally, an adjustable resistance device may be provided so that the user can match exercise effort with his or her personal exercise preferences and goals.
The exercise device should be configured as a small, reconfigurable lightweight multi-bar linkage that allows the position of various links to be rigidly fixed and other links to be rigidly connected to each other to selectively enable various modes of operation (i.e. exercise motions). These exercise motions may include: an “elliptical” motion, a “slider” motion, a “stepping” motion, and a “bicycle” motion to name a few. The “elliptical” motion is further divided into two options. The first “elliptical” option is provided when the user is standing above the exercise device where a “stepping elliptical” motion is achieved. The second “elliptical” motion is provided when the user is sitting. Depending on the size of the exercise device, the inertial resistance of the multi-bar linkage may be sufficient to provide a desired level of resistance to the exercise motion. If desired, the output shaft of the five-bar linkage may be connected to an inertial load such as a flywheel to provide additional resistance to the exercise motion.
Alternatively, the output shaft may be connected to an adjustable resistance device. Although it is possible to use a variety of different resistance devices, the once acceptable resistance device is a planetary gear train assembly that could be mounted in a frame and having a first input, a second input and an output, a mechanism for setting the second input to zero by fixing the second input to the frame, a mechanism for setting the output to zero by appropriate selection of the parameters of the output, so that when the output is loaded with an adjustable force or torque, the power or motion applied to the first input produces no output and is dissipated as frictional energy thereby providing resistance to the power or motion applied to the first input. This device is desired because of its small size, lightweight, ease of adjustability, reliability, quietness, and low cost. The user provides input motion to the device. The users legs and feet can provide the input motion. When operated by the user's legs and feet, the desired exerciser is positioned relative to a chair or couch in which the user sits and it is held and/or mounted so that it does not move under the action of the exercise forces. Alternatively, the exerciser may be placed on a table or other surface and operated by the user's hands and arms.